var login_box = document.querySelector(".login_box");
var register = document.querySelector(".register");
var login_btn = document.querySelector(".login_btn");
var reg_btn = document.querySelector(".reg_btn");
var back = document.querySelector(".back");
var login = document.querySelector(".login");

var toggle_btn = document.querySelector(".toggle_btn");
var login = document.querySelector(".login");
var box = document.querySelector(".web");

login_btn.addEventListener("click",function(){
        register.style.display = "none";
        login_box.style.display = "block";
})
reg_btn.addEventListener("click",function(){
        login_box.style.display = "none";
        register.style.display = "block";
})
back.addEventListener("click",function(){
        login.style.display = "none";
        box.style.opacity = "1";
})
toggle_btn.addEventListener("click",function(){
    login.style.display = "block";
    box.style.opacity = "0.5";
})
        